Araneus gemmoides

Distinguished from other Araneus species by the paired horn-like projections on the abdomen. Differs from Araneus gemma (also called cat-faced spider) by geographic range and subtle morphological details. Separated from Araneus diadematus (cross spider) by the presence of abdominal humps rather than a cross-shaped pattern. The white vertical stripe with chevrons helps distinguish it from similarly colored orb-weavers. Males are identified by their smaller size, longer legs relative to body, and modified pedipalps.

Medium to large orb-weaver with two distinct conical humps on the anterior dorsal abdomen, creating a cat-faced silhouette. Coloration varies from tan and brown to orange and gray, with markings that reinforce the feline appearance. A short white vertical stripe on the front edge of the abdomen, crossed by two white chevrons, is a reasonably consistent mark. Gravid females have greatly enlarged abdomens. Mature females measure 13–25 mm in body length; males are 5–8 mm. Young spiderlings have exaggerated abdominal humps relative to body size.

Builds webs near outdoor lights, building sides, under overhangs, and in protected spaces such as animal burrows. Occupies edge habitats where artificial lighting attracts insect prey. Uses a curled leaf or other retreat connected to the web hub by signal threads. Found in both natural and human-modified environments, including porches, decks, and window frames.

North America: Canada (British Columbia, Saskatchewan, Alberta, Manitoba) and United States (Michigan, Dakotas, Rocky Mountain states, Pacific states, Arizona). Occurs from British Columbia and Saskatchewan east to Michigan, and south through the Rocky Mountains and Pacific states to Arizona.

Adults mature in late summer and are active through fall. Mature individuals observed from August through first hard frost. Egg sacs overwinter, with spiderlings emerging the following spring (typically May–June). Females die within days of laying eggs in late autumn.

Captures flying insects in orb-webs, including fish flies, house flies, mosquitoes, moths, and other small arthropods. Has been observed capturing and consuming other small spiders. Does not prey on ants.

Annual life cycle. Females produce a single egg sac containing hundreds of eggs in late autumn. Spiderlings emerge in spring, initially remaining clustered near the egg sac. After molting, they disperse by ballooning on silk strands carried by air currents. Cannibalism among sibling spiderlings has been observed. Adults do not survive winter; only egg sacs overwinter.

Nocturnal web-builder that repairs or rebuilds webs at night, then occupies the hub head-down to await prey. By day, hides in a retreat connected to the web by signal threads to detect vibrations. Vibrates web when disturbed by large animals; drops from web on dragline if disturbance persists. Modifies web orientation perpendicular to light sources to increase prey capture, and orients webs parallel to wind to reduce damage. Mature males cease web-building and become nomadic, searching for females. Females may relocate webs periodically, consuming old web material before rebuilding.

Predator of flying insects, contributing to natural pest control in urban and suburban environments. Prey for mud dauber wasps (Sceliphron caementarium), which paralyze spiders and provision nests for larvae. Spiderlings serve as food for various predators and are subject to cannibalism.

Considered harmless with low-toxicity venom. Valued as a natural predator of nuisance insects around homes. Frequently observed and fed by homeowners, inspiring public appreciation for spiders. Occasionally brought indoors during cold weather, though this is not recommended. Egg sacs may be inadvertently transported when attached to objects.

• Araneus gemmaShares the common name 'cat-faced spider' and similar abdominal projections, but differs in distribution and specific markings
• Araneus diadematusSimilar orb-web architecture and habitat preference, but distinguished by cross-shaped abdominal pattern rather than paired humps
• Neoscona speciesSimilar web-building behavior and nocturnal habits, but lack distinctive abdominal humps and have different abdominal patterns

The name 'jewel spider' is also applied to Austracantha minax, an unrelated Australian species. Despite intimidating size of mature females, the species poses no medical threat to humans. The common name 'cat-faced spider' leads to confusion with Araneus gemma.

• orb-weaver
• nocturnal
• urban-adapted
• beneficial predator
• annual life cycle
• sexual dimorphism

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Bug Eric: Spider Sunday: Cat-faced Spider
• Bug Eric: Spider Sunday: The Cross Spider
• Arachnida | Beetles In The Bush | Page 5
• Bug Eric: Spider Sunday: Butterfly Orbweaver
• Answer to Super Crop Challenge #2 | Beetles In The Bush
• Do Chestnut, Lemon, or Peppermint Scents Repel Spiders?
• Orb‐web Orientation and Modification by the Spiders Araneus diadematus and Araneus gemmoides (Araneae: Araneidae) in Response to Wind and Light